Semiconductor device including transmission lines and method of forming the same

ABSTRACT

A method of making a semiconductor device includes forming a first transmission line over a substrate. The method includes forming a second transmission line over the substrate. The method further includes depositing a high-k dielectric material between the first transmission line and the second transmission line, wherein the high-k dielectric material partially covers each of the first transmission line and the second transmission line. The method further includes depositing a dielectric material directly contacting the high-k dielectric material, wherein the dielectric material has a different dielectric constant from the high-k dielectric material, and the dielectric material directly contacts the first transmission line or the second transmission line.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.17/587,581, filed Jan. 28, 2022, which is a continuation of U.S.application Ser. No. 16/734,976, filed Jan. 6, 2020, now U.S. Pat. No.11,258,151, issued Feb. 22, 2022, which is a continuation of U.S.application Ser. No. 15/696,337, filed Sep. 6, 2017, now U.S. Pat. No.10,530,030, which is a continuation of U.S. application Ser. No.14/748,524, filed Jun. 24, 2015, now U.S. Pat. No. 9,786,976, issuedOct. 10, 2017, which are incorporated herein by references in theirentireties.

BACKGROUND

Transmission lines are used to transfer signals between portions of acircuit or system. Transmission lines are often used in radio frequency(RF) circuits. In some approaches, a pair of transmission lines calleddifferential transmission lines are used to transfer signals betweenseparate portions of the circuit or system. As technology nodes forcircuits decrease, spacing between adjacent transmission linesdecreases.

Unlike conductive lines in an interconnect structure, transmission linesare used to carry signals having alternating current (AC) signals. Alength of transmission lines is sufficiently long that a wave nature ofthe transferred signal impacts performance of the transmission line. Incontrast, conductive lines in interconnect structures are often formedwithout consideration for a wave nature of a signal along the conductiveline.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a perspective view of a transmission line design according tosome embodiments.

FIG. 2 is a perspective view of a transmission line design according tosome embodiments.

FIGS. 3A and 3B are cross-sectional views of transmission line designsaccording to some embodiments.

FIGS. 4A-4C are cross-sectional views of transmission line designsaccording to some embodiments.

FIGS. 5A and 5B are cross-sectional views of transmission line designsaccording to some embodiments.

FIG. 6 is a flowchart of a method of making a transmission designaccording to some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

As spacing between adjacent transmission lines decreases, a risk forcross talk between the transmission lines increases. Differentialtransmission lines are used to transfer two separate signals forcomparison at a receiving end of the transmission lines, so cross talkbetween differential transmission lines would negatively impact aprecision of the signal comparison. In some approaches, an organicdielectric layer is used to separate adjacent transmission lines.However, the organic dielectric layer often does not provide sufficientisolation between the adjacent transmission lines at high frequencies ofabout 1 gigahertz (GHz) or more. A high-k dielectric material betweenadjacent transmission lines helps to increase isolation between thetransmission lines in order to reduce the risk of cross talk between thetransmission lines.

Inclusion of the high-k dielectric material between the transmissionlines helps to improve impedance matching in the transmission lines.Impedance is an opposition of the transmission lines to transfer energyof signals along the transmission lines. As a frequency of the signalsvaries, the impedance will also vary. By increasing isolation betweenadjacent transmission lines, variation in the impedance due to crosstalk between the transmission lines is decreased, which helps tofacilitate impedance matching. Impedance matching helps to maintainprecise operation of circuitry which depends on the signals from thetransmission lines. Impedance matching is a greater concern as afrequency of the transferred signals increases.

Inclusion of the high-k dielectric material between the transmissionlines also helps to control quadrature amplitude modulation (QAM). QAMis a modulation scheme used to transfer multiple signals along a sametransmission line. QAM involves modulating amplitudes and/or modulatingphases of signals in order to distinguish between the multiple signalsalong the same transmission line.

FIG. 1 is a perspective view of a transmission line design 100 accordingto some embodiments. Transmission line design 100 includes a substrate110, a first transmission line 120 a and a second transmission line 120b over the substrate. A high-k dielectric material 130 is between firsttransmission line 120 a and second transmission line 120 b. A dielectricmaterial 140, different from high-k dielectric material 130, surroundsfirst transmission line 120 a, second transmission line 120 b and thehigh-k dielectric material.

Substrate 110 is configured to provide mechanical support for firsttransmission line 120 a and second transmission line 120 b. In someembodiments, substrate 110 includes silicon, germanium, SiGe or anothersuitable semiconductor material. In some embodiments, substrate 110 is asemiconductor-on-insulator substrate. In some embodiments, substrate 110is a printed circuit board (PCB). In some embodiments, substrate 110 isalso configured to support active circuitry, such as transistors. Insome embodiments, substrate 110 is also configured to support conductivelines in an interconnect structure, which are separate from firsttransmission line 120 a and second transmission line 120 b.

First transmission line 120 a is configured to transfer at least onesignal from one element in a system or circuit to another element in thesystem or circuit. In some embodiments, first transmission line 120 a isconfigured to transfer multiple signals simultaneously. In someembodiments, the multiple signals are modulated with respect to eachother. In some embodiments, first transmission line 120 a includescopper, aluminum, tungsten, alloys thereof or other suitable conductivematerials. In some embodiments, first transmission line 120 a includesgraphene or another suitable conductive element.

Second transmission line 120 b is configured to transfer at least onesignal from one element in the system or circuit to the other element inthe system or circuit. In some embodiments, the at least one signaltransferred by second transmission line 120 b is a differential signalwith respect to a signal transferred by first transmission line 120 a.In some embodiments, the at least one signal transferred by secondtransmission line 120 b is not a differential signal with respect to asignal transferred by first transmission line 120 a. In someembodiments, second transmission line 120 b is configured to transfermultiple signals simultaneously. In some embodiments, the multiplesignals are modulated with respect to each other. In some embodiments,second transmission line 120 b includes copper, aluminum, tungsten,alloys thereof or other suitable conductive materials. In someembodiments, first transmission line 120 a includes graphene or anothersuitable conductive element. In some embodiments, a material of secondtransmission line 120 b is a same material as second transmission line120 b. In some embodiments, the material of first transmission line 120a is different from the material of second transmission line 120 b.

High-k dielectric material 130 is configured to increase isolationbetween first transmission line 120 a and second transmission line 120b. By increasing isolation between first transmission line 120 a andsecond transmission line 120 b, reliability of circuitry connected tothe first transmission line and the second transmission line isincreased due to the increased impedance matching and reduced crosstalk. In some embodiments, a dielectric constant of high-k dielectricmaterial 130 ranges from about 10 to about 20,000 at 1 GHz. If thedielectric constant is too low, then high-k dielectric material 130 doesnot provide sufficient isolation between first transmission line 120 aand second transmission line 120 b, in some instances. If the dielectricconstant is too high, then high-k dielectric material 130 is difficultto reliably manufacture, in some instances. In some embodiments, thedielectric constant of high-k dielectric material 130 ranges from about7,000 to about 12,000. This narrower range provides increased isolationin comparison with lower dielectric constant values and increases easeof manufacture in comparison with other approaches, in some instances.In some embodiments, the dielectric constant of high-k dielectricmaterial 130 is about 10,000.

In some embodiments, high-k dielectric material 130 includes adielectric material such as BaTiO₃, SiO₂, HfO₂, ZrO₂, TiO₂, La₂O₃,SrTiO₃, ZrSiO₄, HfSiO₄, or other suitable dielectric materials. In someembodiments, high-k dielectric material 130 includes the dielectricmaterial and a mixing agent such as resin, ink, epoxy, polyimide oranother suitable mixing agent in order to increase ease of manufactureof the high-k dielectric material.

Transmission line design 100 includes a top surface of high-k dielectricmaterial 130 being substantially coplanar with a top surface of firsttransmission line 120 a and second transmission line 102 b. In someembodiments, high-k dielectric material 130 is formed by screenprinting, photolithography, inkjet printing or another suitableformation process.

Dielectric material 140 is configured to provide isolation between firsttransmission line 120 a, second transmission line 120 b and surroundingelements. In some embodiments, additional transmission lines are locatedwithin dielectric material 140. In some embodiments, an interconnectstructure is located within dielectric material 140. Dielectric material140 is different from high-k dielectric material 130. In someembodiments, dielectric material 140 is an organic dielectric material.In some embodiments, dielectric material 140 includes an epoxy,polyimide, benzocyclobutene (BCB), polybenzoxazole (PBO) or anothersuitable dielectric material. Dielectric material 140 is a samethickness as corresponding dielectric materials in transmission linedesigns which do not include high-k dielectric material 130.

In operation of transmission line design 100, a first signal istransferred through first transmission line 120 a and a second signal istransferred through second transmission line 120 b. A total inductanceof transmission line design 100 is determined based on an inductance offirst transmission line 120 a, an inductance of second transmission line120 b, and a joint inductance between the first transmission line andthe second transmission line. In situations where the first signal andthe second signal are transferred in a same direction, the jointinductance is added to the inductance of first transmission line 120 aand the inductance of second transmission line 120 b. In situationswhere the first signal and the second signal are transferred in oppositedirections, the joint inductance is subtracted from a sum of theinductance of first transmission line 120 a and the inductance of secondtransmission line 120 b. Including high-k dielectric material 130reduces a magnitude of the joint inductance. By reducing a magnitude ofthe joint inductance, designing circuitry connected to firsttransmission line 120 a and second transmission line 120 b is simplifiedbecause the impedance of transmission line design 100 is less dependenton the joint inductance.

FIG. 2 is a perspective view of a transmission line design 200 inaccordance with some embodiments. Elements in transmission line design200 which are the same as elements in transmission line design 100 (FIG.1 ) have a same reference number increased by 100. In comparison withtransmission line design 100, transmission line design 200 includessecond transmission line 220 b on a different level with respect tofirst transmission line 220 a. A different level means that a distancebetween second transmission line 220 b and substrate 210 is differentfrom a distance between first transmission line 220 a and the substrate.

High-k dielectric material 230 remains between first transmission line220 a and second transmission line 220 b. In contrast with high-kdielectric material 130 (FIG. 1 ), high-k dielectric material 230 isbetween first transmission line 220 a and second transmission line 220 bin a direction perpendicular to a top surface of substrate 210. In someembodiments, a combination of first transmission line 220 a, high-kdielectric material 230 and second transmission line 220 b is called atransmission line stack. In some embodiments, multiple transmission linestacks are present in dielectric material 140.

FIG. 3A is a cross-sectional view of a transmission line design 300 inaccordance with some embodiments. Elements in transmission line design300 which are the same as elements in transmission line design 100 (FIG.1 ) have a same reference number increased by 200. In comparison withtransmission line design 100, transmission line design 300 includeshigh-k dielectric material 330 extending over a top surface of firsttransmission line 320 a and second transmission line 320 b and coveringboth sidewalls of each of the first transmission line and the secondtransmission line. In comparison with high-k dielectric material 130,high-k dielectric material 330 helps to increase isolation between firsttransmission line 320 a and surrounding elements; and between secondtransmission line 320 b and surrounding elements.

In some embodiments which include additional transmission lines on adifferent level from first transmission line 320 a and secondtransmission line 320 b, high-k dielectric material 330 helps toincrease isolation of the first and second transmission lines from theadditional transmission lines in comparison with high-k dielectricmaterial 130 (FIG. 1 ). In some embodiments which include aninterconnect structure in dielectric material 340, high-k dielectricmaterial 330 helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 130.

In comparison with transmission line design 100 (FIG. 1 ), transmissionline design 300 has a higher production cost due to the increase in theamount of high-k dielectric material 330 relative to high-k dielectricmaterial 130.

In some embodiments, a top surface of high-k dielectric material 330 issubstantially co-planar with a top surface of first transmission line320 a and second transmission line 320 b; but high-k dielectric material330 still surrounds sidewalls of the first and second transmissionlines.

FIG. 3B is a cross-sectional view of a transmission line design 300′ inaccordance with some embodiments. Elements in transmission line design300′ which are the same as elements in transmission line design 100(FIG. 1 ) have a same reference number increased by 200. In comparisonwith transmission line design 300 (FIG. 3A), transmission line design300′ includes high-k dielectric material 330′ extending over a portionof a top surface of first transmission line 320 a and secondtransmission line 320 b and exposing sidewalls of each of the firsttransmission line and the second transmission line farthest from theadjacent transmission line. In comparison with high-k dielectricmaterial 130, high-k dielectric material 330′ helps to increaseisolation between first transmission line 320 a and surroundingelements; and between second transmission line 320 b and surroundingelements. In some embodiments, high-k dielectric material 330′ extendsover an entirety of the top surface of first transmission line 320 a andsecond transmission line 320 b.

In some embodiments which include additional transmission lines on adifferent level from first transmission line 320 a and secondtransmission line 320 b, high-k dielectric material 330′ helps toincrease isolation of the first and second transmission lines from theadditional transmission lines in comparison with high-k dielectricmaterial 130 (FIG. 1 ). In some embodiments which include aninterconnect structure in dielectric material 340, high-k dielectricmaterial 330′ helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 130.

In comparison with transmission line design 100 (FIG. 1 ), transmissionline design 300′ has a higher production cost due to the increase in theamount of high-k dielectric material 330′ relative to high-k dielectricmaterial 130.

FIG. 4A is a cross-sectional view of a transmission line design 400 inaccordance with some embodiments. Elements in transmission line design400 which are the same as elements in transmission line design 200 (FIG.2 ) have a same reference number increased by 200. In comparison withtransmission line design 200, transmission line design 400 includeshigh-k dielectric material 430 extending over a top surface of firsttransmission line 420 a and second transmission line 420 b and coveringboth sidewalls of each of the first transmission line and the secondtransmission line. In comparison with high-k dielectric material 230,high-k dielectric material 430 helps to increase isolation between firsttransmission line 420 a and surrounding elements; and between secondtransmission line 420 b and surrounding elements.

In some embodiments which include additional transmission lines on asame level as at least one of first transmission line 420 a or secondtransmission line 420 b, high-k dielectric material 430 helps toincrease isolation of the first and second transmission lines from theadditional transmission lines in comparison with high-k dielectricmaterial 230 (FIG. 2 ). In some embodiments which include aninterconnect structure in dielectric material 440, high-k dielectricmaterial 430 helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 230.

In comparison with transmission line design 200 (FIG. 2 ), transmissionline design 400 has a higher production cost due to the increase in theamount of high-k dielectric material 430 relative to high-k dielectricmaterial 230.

FIG. 4B is a cross-sectional view of a transmission line design 400′ inaccordance with some embodiments. Elements in transmission line design400′ which are the same as elements in transmission line design 200(FIG. 2 ) have a same reference number increased by 200. In comparisonwith transmission line design 400 (FIG. 4A), transmission line design400′ includes high-k dielectric material 430′ extending over a portionof a sidewall surfaces of first transmission line 420 a and secondtransmission line 420 b and exposing the top surface of the secondtransmission line. In comparison with high-k dielectric material 230,high-k dielectric material 430′ helps to increase isolation betweenfirst transmission line 420 a and surrounding elements; and betweensecond transmission line 420 b and surrounding elements. In someembodiments, high-k dielectric material 430′ extends over less than anentirety of the sidewall surfaces of at least one of first transmissionline 420 a or second transmission line 420 b.

In some embodiments which include additional transmission lines on asame level as at least one of first transmission line 420 a or secondtransmission line 420 b, high-k dielectric material 430′ helps toincrease isolation of the first and second transmission lines from theadditional transmission lines in comparison with high-k dielectricmaterial 230 (FIG. 2 ). In some embodiments which include aninterconnect structure in dielectric material 440, high-k dielectricmaterial 430′ helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 230.

In comparison with transmission line design 200 (FIG. 2 ), transmissionline design 400′ has a higher production cost due to the increase in theamount of high-k dielectric material 430′ relative to high-k dielectricmaterial 230.

FIG. 4C is a cross-sectional view of a transmission line design 400″ inaccordance with some embodiments. Elements in transmission line design400″ which are the same as elements in transmission line design 200(FIG. 2 ) have a same reference number increased by 200. In comparisonwith transmission line design 400 (FIG. 4A) and transmission line design400′ (FIG. 4B), transmission line design 400″ includes high-k dielectricmaterial 430″ extending over a portion of sidewall surfaces of firsttransmission line 420 a and exposed sidewalls and top surface of secondtransmission line 420 b. In comparison with high-k dielectric material230, high-k dielectric material 430″ helps to increase isolation betweenfirst transmission line 420 a and surrounding elements; and betweensecond transmission line 420 b and surrounding elements. In someembodiments, high-k dielectric material 430″ extends over less than anentirety of the sidewall surfaces of first transmission line 420 a.

In some embodiments which includes additional transmission lines on asame level as at least one of first transmission line 420 a or secondtransmission line 420 b, high-k dielectric material 430″ helps toincrease isolation of the first and second transmission lines from theadditional transmission lines in comparison with high-k dielectricmaterial 230 (FIG. 2 ). In some embodiments which includes aninterconnect structure in dielectric material 440, high-k dielectricmaterial 430″ helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 230.

In comparison with transmission line design 200 (FIG. 2 ), transmissionline design 400″ has a higher production cost due to the increase in theamount of high-k dielectric material 430″ relative to high-k dielectricmaterial 230.

FIG. 5A is a cross-sectional view of a transmission line design 500 inaccordance with some embodiments. Elements in transmission line design500 which are the same as elements in transmission line design 100 (FIG.1 ) have a same reference number increased by 400. In comparison withtransmission line design 100, transmission line design 500 is a co-axialarrangement of first transmission line 520 a and second transmissionline 520 b. Transmission line design 500 includes high-k dielectricmaterial 530 extending over an outer surface of first transmission line520 a and second transmission line 520 b. In comparison with high-kdielectric material 130, high-k dielectric material 530 helps toincrease isolation between first transmission line 520 a and surroundingelements; and between second transmission line 520 b and surroundingelements.

In some embodiments which include additional transmission lines on asame level or different level from as at least one of first transmissionline 520 a or second transmission line 520 b, high-k dielectric material530 helps to increase isolation of the first and second transmissionlines from the additional transmission lines in comparison with high-kdielectric material 130 (FIG. 1 ). In some embodiments which include aninterconnect structure in dielectric material 540, high-k dielectricmaterial 530 helps to increase isolation of the first and secondtransmission lines from the interconnect structure in comparison withhigh-k dielectric material 130.

In comparison with transmission line design 100 (FIG. 1 ), transmissionline design 500 has a higher production cost due to the increase in theamount of high-k dielectric material 530 relative to high-k dielectricmaterial 130; and because of additional processing used to form thecoaxial arrangement in transmission line design 500.

FIG. 5B is a cross-sectional view of a transmission line design 500′ inaccordance with some embodiments. Elements in transmission line design500′ which are the same as elements in transmission line design 100(FIG. 1 ) have a same reference number increased by 400. In comparisonwith transmission line design 500 (FIG. 5A), transmission line design500′ includes high-k dielectric material 430′ extending over an outersurface of second transmission line 520 b and exposing the outer surfaceof first transmission line 520 a. In comparison with high-k dielectricmaterial 130, high-k dielectric material 530′ helps to increaseisolation between second transmission line 520 b and surroundingelements.

In some embodiments, multiple coaxially arranged transmission lines areincluded in a transmission line design. In some embodiments, at leastone coaxial arrangement includes high-k dielectric material over anouter surface of an outer-most transmission line, as in transmissionline design 500 (FIG. 5A) and at least one coaxial arrangement includeshigh-k dielectric material exposing an outer surface of an outer-mosttransmission line, as in transmission line design 500′ (FIG. 5B).

In some embodiments, more than two transmission lines are coaxiallyarranged. In some embodiments, an outer surface of an outer-mosttransmission line is exposed by high-k dielectric material. In someembodiments, the outer surface of an outer-most transmission line iscovered by high-k dielectric material.

FIG. 6 is a flowchart of a method 600 of forming a transmission linedesign in accordance with some embodiments. In operation 602, a firsttransmission line is formed on a substrate. The first transmission line,e.g., first transmission line 120 a (FIG. 1 ), first transmission line220 a (FIG. 2 ), first transmission line 320 a (FIGS. 3A-3B), firsttransmission line 420 a (FIG. 4A-4C), or first transmission line 520 a(FIGS. 5A-5B), is usable to transfer at least one signal from oneelement in a circuit or system to another element in the circuit orsystem. In some embodiments, the first transmission line is formed byplating, physical vapor deposition (PVD), chemical vapor deposition(CVD), atomic layer deposition (ALD), or another suitable formationprocess. In some embodiments, the first transmission line is formed indirect contact with the substrate. In some embodiments, the firsttransmission line is formed spaced apart from the substrate.

In operation 604, a second transmission line is formed on a substrate.The second transmission line, e.g., second transmission line 120 b (FIG.1 ), second transmission line 220 b (FIG. 2 ), second transmission line320 b (FIGS. 3A-3B), second transmission line 420 b (FIG. 4A-4C), orsecond transmission line 520 b (FIGS. 5A-5B), is usable to transfer atleast one signal from one element in a circuit or system to anotherelement in the circuit or system. In some embodiments, the secondtransmission line is formed by plating, PVD, CVD, ALD, or anothersuitable formation process. In some embodiments, the first transmissionline is formed using a same process as the process used to form thesecond transmission line. In some embodiments, the first transmissionline is formed using a different process from the process used to formthe second transmission line.

In some embodiments, the second transmission line is formed in directcontact with the substrate. In some embodiments, the second transmissionline is formed spaced apart from the substrate. In some embodiments, thefirst transmission line is formed on a same level as the secondtransmission line. In some embodiments, the first transmission line isformed on a different level from the second transmission line.

In some embodiments, the first transmission line is formedsimultaneously with the second transmission line. In some embodiments,the first transmission line is formed sequentially with the secondtransmission line. In some embodiments, a first portion of the firsttransmission line is formed prior to formation of the secondtransmission line; and a second portion of the first transmission lineis formed after formation of the second transmission line.

In operation 606, a high-k dielectric material is formed on thesubstrate. The high-k dielectric material, e.g., high-k dielectricmaterial 130 (FIG. 1 ), high-k dielectric material 230 (FIG. 2 ), high-kdielectric material 330 (FIG. 3A), high-k dielectric material 330′ (FIG.3B), high-k dielectric material 430 (FIG. 4A), high-k dielectricmaterial 430′ (FIG. 4B), high-k dielectric material 430″ (FIG. 4C),high-k dielectric material 530 (FIG. 5A), or high-k dielectric material530′ (FIG. 5B), is configured to increase isolation between the firsttransmission line and the second transmission line. In some embodiments,the high-k dielectric material is formed using screen printing,photolithography, inkjet printing or another suitable formation process.

An order of operations 602, 604 and 606 depends on a structure of thetransmission line design to be formed. In some embodiments where thefirst transmission line and the second transmission line are on a samelevel, operation 606 is performed after operations 602 and 604 areperformed. In some embodiments where the first transmission line and thesecond transmission line are on a same level, operation 606 is performedafter one of operations 602 or 604 is performed. In some embodimentswhere the first transmission line and the second transmission line areon different levels, operation 606 is performed prior to operation 604.

In some embodiments, the high-k dielectric material is formed before atleast one of the first transmission line or the second transmissionline. In some embodiments, the high-k dielectric material is formedafter both of the first transmission line and the second transmissionline. In some embodiments, a first portion of the high-k dielectricmaterial is formed prior to at least one of the first transmission lineor the second transmission line; and a second portion of the high-kdielectric material is formed after at least one of the firsttransmission line or the second transmission line.

In operation 608, a dielectric material is formed around the high-kdielectric material, the first transmission line, and the secondtransmission line. The dielectric material, e.g., dielectric material140 (FIG. 1 ), dielectric material 240 (FIG. 2 ), dielectric material340 (FIGS. 3A-B), dielectric material 440 (FIGS. 4A-C), or dielectricmaterial 540 (FIG. 5A-B), is configured to provide isolation between thefirst transmission line and surrounding elements; and between the secondtransmission line and the surrounding elements. In some embodiments, thedielectric material is formed using sputtering, PVD, CVD, ALD, printingor another suitable formation process.

In some embodiments, the dielectric material is formed after the high-kdielectric material, the first transmission line, and the secondtransmission line. In some embodiments, the dielectric material isformed prior to at least one of the high-k dielectric material, thefirst transmission line or the second transmission line. In someembodiments, an opening is formed in the dielectric material, usingetching, drilling, or another suitable process, and at least one of thefirst transmission line, the second transmission line or the high-kdielectric material is formed in the opening. In some embodiments wherean opening is formed in the dielectric material, the dielectric materialis used to fill a remaining portion of the opening following formationof the first transmission line, the second transmission line or thehigh-k dielectric material. In some embodiments, a first portion of thedielectric material is formed prior to at least one of the high-kdielectric material, the first transmission line or the secondtransmission line; and a second portion of the dielectric material isformed after at least one of the high-k dielectric material, the firsttransmission line or the second transmission line.

In some embodiments where the transmission line design has a coaxialarrangement, a first portion of the dielectric layer is formed followedby forming a recess in the dielectric layer. A first portion of thefirst transmission line is formed in the recess followed by a firstportion of the high-k dielectric layer and then the second transmissionline. In some embodiments, the second transmission line will extendabove a top surface of the first portion of the dielectric layer.Following formation of the second transmission line, a second portion ofthe high-k dielectric layer is formed over the second transmission lineto enclose the second transmission line with the first and secondportions of the high-k dielectric material. A second portion of thefirst transmission line is then formed over the high-k dielectricmaterial to enclose the high-k dielectric material in the first portionand the second portion of the first transmission line.

In some embodiments, an order of operations in method 600 is changedbased on an arrangement of the high-k dielectric material, the firsttransmission line and the second transmission line in the transmissionline design. In some embodiments, additional operations are included inmethod 600, such as patterning processes, planarization process,cleaning processes, or other suitable processes.

An aspect of this description relates to a method of making asemiconductor device. The method includes forming a first transmissionline over a substrate. The method includes forming a second transmissionline over the substrate. The method further includes depositing a high-kdielectric material between the first transmission line and the secondtransmission line, wherein the high-k dielectric material partiallycovers each of the first transmission line and the second transmissionline. The method further includes depositing a dielectric materialdirectly contacting the high-k dielectric material, wherein thedielectric material has a different dielectric constant from the high-kdielectric material, and the dielectric material directly contacts thefirst transmission line or the second transmission line. In someembodiments, forming the second transmission line comprise forming thesecond transmission line having a top-most surface coplanar with atop-most surface of the first transmission line. In some embodiments,depositing the dielectric material comprises depositing the dielectricmaterial in direct contact with the first transmission line. In someembodiments, depositing the dielectric material comprises depositing thedielectric material in direct contact with the second transmission line.In some embodiments, depositing the high-k dielectric material comprisesfilling a space between the first transmission line and the secondtransmission line with the high-k dielectric material. In someembodiments, depositing the dielectric material comprises depositing thedielectric material contacting a sidewall of the first transmission lineand contacting a sidewall of the second transmission line. In someembodiments, depositing the dielectric material comprises depositing thedielectric material in direct contact with the high-k dielectricmaterial.

An aspect of this description relates to a method of makingsemiconductor device. The method includes forming a first transmissionline over a substrate. The method further includes forming a secondtransmission line over the substrate. The method further includesdepositing a high-k dielectric material between the first transmissionline and the second transmission line, wherein an entirety of the secondtransmission line is above the high-k dielectric material. The methodfurther includes depositing a dielectric material directly contactingthe high-k dielectric material, wherein the dielectric material has adifferent dielectric constant from the high-k dielectric material, thedielectric material directly contacts the second transmission line, andthe dielectric material is separated from the first transmission line.In some embodiments, depositing the high-k dielectric material comprisesdepositing the high-k dielectric material along a top-most surface andalong sidewalls of the first transmission line. In some embodiments,forming the second transmission line comprises forming the secondtransmission line in direct contact with the high-k dielectric material.In some embodiments, forming the first transmission line comprisesforming the first transmission line comprising copper, aluminum,tungsten, or graphene. In some embodiments, forming the secondtransmission line comprises forming the second transmission lineincluding a same material as the first transmission line. In someembodiments, depositing the high-k dielectric material comprisesdepositing the high-k dielectric material having a dielectric constantranging from about 10 to about 20,000 at 1 Gigahertz (GHz). In someembodiments, depositing the dielectric material comprises depositing thedielectric material in direct contact with a top-most surface of thehigh-k dielectric material.

An aspect of this description relates to a semiconductor device. Thesemiconductor device includes a first transmission line. Thesemiconductor device includes a second transmission line, wherein thefirst transmission line is concentric with the second transmission line.The semiconductor device further includes a first high-k dielectriclayer between the first transmission line and the second transmissionline. The semiconductor device further includes a second high-kdielectric material surrounding the first transmission line, wherein thefirst high-k dielectric layer is concentric with the second high-kdielectric layer. In some embodiments, the semiconductor device furtherincludes a dielectric material in direct contact with the second high-kdielectric material. In some embodiments, the dielectric material isseparated from both the first transmission line and the secondtransmission line. In some embodiments, the first high-k dielectricmaterial comprises a same material as the second high-k dielectricmaterial. In some embodiments, the first transmission line comprisescopper, aluminum, tungsten, or graphene. In some embodiments, the secondtransmission line comprises a same material as the first transmissionline.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of making a semiconductor devicecomprising: forming a first transmission line over a substrate; forminga second transmission line over the substrate; depositing a high-kdielectric material between the first transmission line and the secondtransmission line, wherein the high-k dielectric material partiallycovers each of the first transmission line and the second transmissionline; and depositing a dielectric material directly contacting thehigh-k dielectric material, wherein the dielectric material has adifferent dielectric constant from the high-k dielectric material, andthe dielectric material directly contacts the first transmission line orthe second transmission line.
 2. The method of claim 1, wherein formingthe second transmission line comprise forming the second transmissionline having a top-most surface coplanar with a top-most surface of thefirst transmission line.
 3. The method of claim 1, wherein depositingthe dielectric material comprises depositing the dielectric material indirect contact with the first transmission line.
 4. The method of claim3, wherein depositing the dielectric material comprises depositing thedielectric material in direct contact with the second transmission line.5. The method of claim 1, wherein depositing the high-k dielectricmaterial comprises filling a space between the first transmission lineand the second transmission line with the high-k dielectric material. 6.The method of claim 1, wherein depositing the dielectric materialcomprises depositing the dielectric material contacting a sidewall ofthe first transmission line and contacting a sidewall of the secondtransmission line.
 7. The method of claim 1, wherein depositing thedielectric material comprises depositing the dielectric material indirect contact with the high-k dielectric material.
 8. A method ofmaking semiconductor device comprising: forming a first transmissionline over a substrate; forming a second transmission line over thesubstrate; depositing a high-k dielectric material between the firsttransmission line and the second transmission line, wherein an entiretyof the second transmission line is above the high-k dielectric material;and depositing a dielectric material directly contacting the high-kdielectric material, wherein the dielectric material has a differentdielectric constant from the high-k dielectric material, the dielectricmaterial directly contacts the second transmission line, and thedielectric material is separated from the first transmission line. 9.The method of claim 8, wherein depositing the high-k dielectric materialcomprises depositing the high-k dielectric material along a top-mostsurface and along sidewalls of the first transmission line.
 10. Themethod of claim 8, wherein forming the second transmission linecomprises forming the second transmission line in direct contact withthe high-k dielectric material.
 11. The method of claim 8, whereinforming the first transmission line comprises forming the firsttransmission line comprising copper, aluminum, tungsten, or graphene.12. The method of claim 11, wherein forming the second transmission linecomprises forming the second transmission line including a same materialas the first transmission line.
 13. The method of claim 8, whereindepositing the high-k dielectric material comprises depositing thehigh-k dielectric material having a dielectric constant ranging fromabout 10 to about 20,000 at 1 Gigahertz (GHz).
 14. The method of claim8, wherein depositing the dielectric material comprises depositing thedielectric material in direct contact with a top-most surface of thehigh-k dielectric material.
 15. A semiconductor device comprising: afirst transmission line; a second transmission line, wherein the firsttransmission line is concentric with the second transmission line; afirst high-k dielectric layer between the first transmission line andthe second transmission line; and a second high-k dielectric materialsurrounding the first transmission line, wherein the first high-kdielectric layer is concentric with the second high-k dielectric layer.16. The semiconductor device of claim 15, further comprising adielectric material in direct contact with the second high-k dielectricmaterial.
 17. The semiconductor device of claim 16, wherein thedielectric material is separated from both the first transmission lineand the second transmission line.
 18. The semiconductor device of claim15, wherein the first high-k dielectric material comprises a samematerial as the second high-k dielectric material.
 19. The semiconductordevice of claim 15, wherein the first transmission line comprisescopper, aluminum, tungsten, or graphene.
 20. The semiconductor device ofclaim 19, wherein the second transmission line comprises a same materialas the first transmission line.